Manually removable crown cap



W. D. WALLACE MANUALLY REMOVABLE CROWN CAP Nov. 16, 1965 2 Sheets-Sheet 1 Filed 00t- 28, 1964 INVENTOR. w/LL/A/w 0 WALLACE BY f# f. WJ. JM# FL H7 Nov. 16, 1965 l w. D. WALLACE 3,217,915

MANUALLY REMOVABLE CROWN CAP Filed Oct. 28, 1964 2 Sheets-Sheet 2 INVENTOR, W/LL/AM D. WALLACE United States Patent C) 3,217,916 MANUALLY REMVABLE (IRUWN CAl? William D. Wallace, Northfield, lll., assigner to National Can Corporation, hicago, lill., .a corporation of Deiaware Filed Oct. 2S, 1964, der. No. @7,115 5 Ciaims. ("i. 21S-4to) This invention relates to a crown cap for containers, such as bottles, cone top cans and the like. More particularly, the invention relates to a crown cap which is readily removable by hand and without the need for using opening tools or the like, and which is otherwise substantially the same as an ordinary crown cap and possesses all the advantages inherent therein.

As is well known, crown caps are universally used, and these caps are commercially desirable to the extent that literally billions of them are sold throughout the world every year.

The crown cap is known to possess the advantages of combining ready sealing, ability to withstand pressure contained in containers for long periods of time, economy of manufacture, simplicity of application, freedom from contamination, and standardization of sizes and dimensions throughout the world. ln addition, the crown cap is relatively simple to manufacture, because it is Symmetrical and comprises only two major components.

These and other advantages are known and accepted, and accordingly there is a great deal to recommend the commercial use of crown caps in tremendous quantities.

In fact, the only real disadvantage of crown caps is that they generally require the use of a hand tool or other external object for their speedy and convenient removal.

Hence, there has long existed a need for a closure which would embody all the advantages of crown caps, but which would be readily openable by the hand or fingers of the person intending to use the contents of the container. Likewise there has been a great need for a closure which would combine all of the advantages known to inhere crown caps, an additionally possess the advantage of an easy opening feature.

However, the requirements for such an easy opening closure seem to impose contradictory requirements on such a closure. Thus, a crown cap incorporating these characteristics requires that at least a portion thereof be weak enough to be opened, torn, or dislodged from its position on top of a container, and yet be strong enough to withstand the pressures of carbonation, and the pres sures caused by heat treating, such as pasteurizing of the contents thereof. In addition, a manually removable crown cap must have the ruggedness to withstand repeated handling, stacking, and the ordinary abuse incident to manufacture, shipment, storage, and sale of the con tainer with the cap attached thereto.

The present invention comprehends the manufacture of a novel crown ca-p which possesses the advantages of ordinary crown caps referred to above, including an ability to be opened by a conventional opener, and other advantages, including those inherent in the invention, as well as the advantages of easy manual opening.

In general, the invention relates to a cap with manually removable tabs in lthe skirt portion of the crown, in combination with an ordinary inner pressure seal of cork composition or a plastisol, and a second, or intermediate, gas-impermeable seaiing member disposed between the cork or other sealant and the inner surface of the crown.

The invention further relates to a crown cap which generally includes U-shaped tabs located at least partly but not necessarily completely in the skirt portion, a first or inner seal, and a second or intermediate seal, and

3,Zi7,9l6 Patented Nov. i6, 1965 further includes lines of weakness in the form of scored or cut through regions, in a variety of forms, on the top of the crown, to facilitate bending of the top portion thereof in order to remove the crown from the container.

Other modifications and variations of such a manually removable crown cap will be discussed further herein.

These and other novel features of the present invention, and further objects and advantages thereof, including those inherent therein, will become more apparent when considered in conjunction with a description of the preferred embodiment of the invention contained in the following specification and claims, and as shown in the accompanying drawings, in which like reference numerals denote corresponding parts throughout, and in which:

FIG. l is an isometric view of a bottle having a crown cap of the present invention attached thereto.

FIG. 2 is a top plan view of the cap of FIG. 1.

FTG. 3 is a side elevational View of the crown cap of the present invention.

FlG. 4 is a vertical sectional view, taken along lines 4--4 of FiG, 2 of the crown cap of FIG.. 2.

FiG. 5 is a vertical sectional View similar to FIG. 4 and showing a modified form of the invention, including a modied inner seal member therein.

FIG. 6 is a greatly enlarged vertical sectional View of a portion of the cap and container of FIG. l and showing the iinger tab means therein.

FIG. 7 is an isometric View of the cap showing it in a partially opened position.

FIG. 8 is an isometric View of a portion of the container and crown cap, showing a somewhat different embodiment of the cap than that shown in FIG. l.

FG. 9 is a top plan view of the modihed form of the invention shown in FIG. 8.

FIG. l0 is a top plan View showing a cap unit somewhat `similar to the uni-t shown in FIG. 2 but differing therefrom in detail.

FiG. 1l is an isometric view of the disc insert or intermediate seal of the present invention.

FG. l2 is a vertical sectional view of the preferred form of the intermediate seal disc ofthe present invention.

FIG. 13 is a vertical sectional view of a crown cap of the present invention and showing the cap unit with a modilied form of an inner seal unit therein.

Referring now to the drawings in greater detail, there is shown generally in FIG. 1 a container 2d such as a bottle or the like, and this container is shown to have a neck portion 22, and, as best shown in FIG. 6, an upper cylindrical extension portion 24, an upper sealing groove 2o and a topmost flange 23 which includes a top sealing surface 3%. The container here is shown as being a bottle but, as will be understood by those skilled in the art, this invention applies equally in all its aspects to equivalents thereof, such as cone top metal containers and the like.

There is also shown a crown cap 32 and this cap is shown to include a generally flat top surface portion 3d and a depending or downwardly extending flange or skirt portion 36. The skirt portion 36 is shown to comprise a series 0f nibs or lands 3d with grooves or valleys 4t) therebetween. In commercial use, crown caps generally contain 21 each of these lands 3S and grooves 40, or flutes, as they are sometimes referred to herein, and in the trade.

Located in the skirt portion 36 are at least two tabs 42 engageable by a finger or finger nail, and these tabs 42 are shown to be defined by cuts d4 which are generally U shaped, with solid or uncut portions d6 joining the bottom portions of the tabs 42 to the lower portion d8 of the skirt 36, for reasons to be discussed more fully herein.

ICC

Other major components of the present invention include an inner seal member 50 of a cork composition or a plastisol, and an intermediate, metal containing, gasimpermeable seal member 52, the construction of which will be described in greater detail hereinafter.

In addition, the top portion 34 of the crown may have slits S4 out therethrough and extending radially inwardly from the outer periphery of the top surface.

Alternatively, in place of cuts 54 there may be scored or embossed lines of weakness 56 extending radially such as those shown in FIG. 9, for example, or lines forming chords connecting the top portions of the tabs tl-2 such as the scored or embossed lines 58 shown in FlG. 9. The purpose of these cuts 54, or the scored or embossed lines 56 or 58 is twofold, that is, these lines permit ready upward folding of a portion 60 of the crown cap to a position such as that shown in FIG. 7 for example, immediately prior to the removal of cap 32 from the container 20. Secondly, the cuts 54 or embossed lines Se provide areas in which a slight lateral shift of the top portion 3d of the crown may take place upon application of pressure by a crowning machine, for reasons which will be referred to in greater detail hereinafter.

Thus, in the case of a tinplate or like cap, the metal is stiff enough so that lines of weakness in the form of the cuts or scores make possible easy bending of the portion of the cap. Therefore, in the construction of a tinplate or a like cap the provision of the cuts, score lines, or ernbossed areas or their equivalent is necessary to produce a satisfactory cap.

The third principal element of the present invention is the metal-containing, substantially gas-impermeable seal member 52 which is disposed between the inner seal 50 and the top portion 34 of the crown. This seal member 52 may be referred herein as the outer seal or the intermediate seal, it being understood that it is the outermost of the two seals proper, but that it is intermediate the top portion 34 of the cap and the inner seal member 5).

The fourth element of the combination is an optional element, and this is the inner Iso-called spot 64 which is often seen in caps used for bottled beer. This spot 6d is ordinarily used by brewers to prevent the acquisition by the beer of a cork taste or flavor, and this spot, by reason of its being made of aluminum foil is thought to enhance the flavor of beer or other malt beverages upon ageing thereof.

This aluminum foil spot 64 however, `does not provide an effective vapor barrier in use, for reasons which are not entirely known, although the fact is well known that such spots do not provide a sealing feature. The spot 64 may be dispensed with when a plastisol type seal 50 is used for beer, and, normally, soft drinks are not bottled with an aluminum spot, 'but some soft drinks may include a vinyl spot in the crown cap. Thus, the spot 64 may be used with the crown caps of the present invention, but does not form an essential part thereof.

Referring now to the tabs 42 or those portions of the crown which are adapted to be grasped by the finger nail of the person seeking to open the bottle, these tabs 42 according to the present invention are spaced apart in the skirt portion 36 of the cap 32 and are generally defined at the top portion thereof by a cut 44 which is, in the upright position of the cap, preferably, but not necessarily, a generally inverted U Shaped cut. This cut extends downwardly somewhat into the flared lower skirt portion 48 of the cap but leaves a bottom portion of the tab 42 integrally attached to the bottom portion 43 of the skirt.

The top portion of the tab 42 extends somewhat into the top portion 34 of the cap 32. The cap 32, for purposes of defining the location of the tab 42, is considered to comprise a generally or approximately flat top portion 34, a lower flange or skirt portion 36, and an intermediate or radius portion which is a curved portion joining the top portion 34 and the skirt portion 36. Thus, the tab 42 preferably extends very slightly into the top. ln general, the tab l2 should not be located entirely in the skirt and radius, because, in this case, the crowner undesirably bends the tabs down in the crowning operation, or strips them from the cap. On the other hand, if the tabs 42 extend too far radially inwardly on the top portion of the crown, they are dillicult to grasp, and are likely to be undesirably crushed downwardly by objects striking the top thereof during handling thereof. Thus, the preferred location of the top of the tab Al2 is toward the top edge of the transition surface 35', or very slightly, such as a few thousandths of an inch, into the top portion proper 34.

As will be noted by reference to FIG. 3 the cut lines 44 define the tab d2 and the lines 44 extend downwardly along the ridges defining the lands or outwardly extending portions 38 of the cap. The location of the tab in this respect facilitates removal of the tab and simplifies manufacture of the improved cap on a commercial scale, and is accordingly preferred, even though such location is not absolutely necessary in accordance with the present invention.

In the commercial embodiment of the invention, three such tabs 42 are provided, equally spaced apart and having the center lines thereof separated by angles of Thus, the cuts 54 or the embossed lines 56 extend radially outwardly from the center of the cap at 120 angles. In use, removal of any two tabs ft2 is sufficient to facilitate opening the container by hand, although three tabs are generally provided as aforesaid, and, the 120 angle or disposition apart of the tabs in the cap is not an absolutely essential feature of the invention. out is generally preferred. It will be noted, particularly in reference to FIG. 6 for example that the tab is removed by an outward and downward bending thereof, thereby breaking the metal in the small junction region 68 where the ybottom of the tab 42 is joined to the remainder of the skirt 36. Thus, when the crown is placed on the container and clamped in position by an inward pressure or force on the lands 38 the crown will retain its sealing strength by reason of the hoop strength of the bottom portion of the crown. Breaking of the junction portion 63 breaks the hoop which is effective to hold the crown in position and facilitate the ready removal thereof.

Referring now to the composition of the outer seal 52, this seal may `comprise any suitable gas-impermeable, somewhat malleable member. Examples of such seal members are steel with a tin coating or so-called tinplate, in thicknesses varying -between 0.00085 inch and about .007 inch; aluminum discs of aluminum foil, in thicknesses varying between about 0.00085 inch and .007 inch, or a thin plastic tape, such as polyethylene terephthalate polyester (Mylar) film or tape with a metal foil backing thereon, such as for example, a metal coating applied by deposition to the tape in a vacuum.

In the case of a disc of tinplate, aluminum or the like, the disc may optionally have a flange member 70 therein which depends downwardly somewhat therefrom, as shown in FIG. ll and FIG. l2, and this flange may be up to about 1/16 of an inch across, for example. The principal advantage of incorporating a flange of this type is that, when the plastisol liner is used, the flange '70 helps prevent leakage of the plastisol out of the slight opening left between the top of the U-tab and the edge of the crown adjacent thereto, and, in the case of the cork inner seal, prevents the thumb nail of the user from undesirably engaging the cork liner proper by deflecting the thumb nail somewhat downwardly against the tab member 42. The flange 70 is not necessary from the standpoint of sealing characteristics, however, but provision therefor is desired for the reason set forth above.

The lining materials used to make up the inner liner referred to in the table below may be of several types, the ordinary metal having cork discs with a resinous binder, so-called I type cork, which is a cork with a gelatin type binder, and any one of a number of com- .5 mercially available plastisol seals, one for example being a grey colored material comprising a vinyl resin dispersed in a plasticizer.

Another seal comprises a clear, polyethylene type resin seal member, and still another seal member is in the form of an O ring seal of a stiffer plastisol than that referred to above. All of such discs and O ring type sealing members are well known in the art and are readily available commercially. The construction of such O ring 72 and its disposition inside the cap unit 32 is illustrated, for example, in FIG. 5.

In use, the crown cap thus made is applied in the ordinary manner with ordinary crown capping equipment, such as a Meyer crowner such as that known to those 'skilled in the art. Caps such as those made in accordance with the present invention have performed satisfactorily when subject to the pressures, temperatures, and volumes of gases as are normally encountered as an incident to pasteurization, storage and handling, etc., such pressures generally being of the order of up to 95 lbs. to 110 lbs. per square inch or more, and temperatures of up to 150 F.

T able I Dise type Inner seal Number Number tested leaked 1. 55 lb. (0.006l) tinplate..u Cork, VN-. 67 0 2. 551i). (0.006l) tinplate1- Cork, MN-.- 67 0 3. 30 lb. (0.0037) tinplate, Cork, 1/4 66 0 4. 0.002 steel foil-. Cork, AW... 26 0 5. Cork, lio' 35 0 6. Plastisol O ring 70 0 7. Grey plastisol 18 0 disc liner.

8. 0.002 steel ioil 3 Cork, A0 233 0 9. Foil covered plastic tape Cork, /4 33 0 (.005" foil with .004" adhesive and tape combination backing). 10. Foil covered plastic tape Cork, Mo 33 0 (.005 foil with .004 adhesives and tape combination backing).

1 This disc did not contain the exterior flange portion 70.

2 This plastisol material is a red-colored material made in England and sold here under the trademark Daraseal and is well known to those skilled in the art. The rings used were 335 lng. each, baked for 1% minutes at 380 F.

3 Crown proper made from 95 lbs. tinplate.

Norm-All crowns were full skirt, made from 100 lbs. base Weight tinplate, except where otherwise indicated.

The above tests worked satisfactorily with Hutchinson brand cork liners or Armstrong J type corks, these being gelatin bonded type cork liners. Other, resinbonded cork liners are also suitable for use with the present invention.

Although the reasons for the operation of the crown cap are not understood with certainty, certain problems of the prior art have been overcome by the use of the cap construction referred to herein.

For example, prior caps containing U shaped tabs similar to the tabs 42 of the present invention have been known, but a crown made only with such tabs, when crimped onto a 'bottle cap will allow leakage of gas therethrough, because there is a tendency for the crown to form a peak at the apex of the cutout, and hence, a region wherein there is low crown pressure against the sealing member is present, which allows leakage. The slit or embossed feature 54, 56 enables portions of the top 34 of the crown to shift very slightly during capping, and this eliminates the peaking eiect and most of the leakage, but some leakage in these crowns is still known to exist. It appears that, in many cases, whereas gas will not penetrate or leak through the inner seal 50 in the region where it is more compressed, such as the region shown as (A) in FIG. 6, where compression thereof is greatest, it will nonetheless leak through in the less dense region directly below the slit 54 or the scored or embossed regions 56, in the one case leaking directly into the atmosphere, and, in the other, along the score line toward the outer tab portions 42, and thence to the atmosphere. As explained above, however, without such score or cut lines 54, 56, 58 caps of the prior art also undesirably leaked gas therethrough, such scored, cut, or embossed lines S4, 56, S8, whether radially disposed or otherwise, facilitate an even discretion of forces in the cap, and, regardless of their exact disposition may -be referred to herein, and are referred to in the claims as lines of weakness, it being understood that such term encompasses all such lines or regions which will bring about this result. Accordingly, it is believed that the provision of the outer seal 52 serves the function of preventing gas leakage through the uncompressed portion of the inner seal 50, thereby resulting in a cap, which, for the iirst time, will retain carbonation pressures attendant to manufacturing, shipping, and processing, and a cap which is nonetheless readily removable by human hands alone. In use, the outer or intermediate seal 52 may be adhered by an adhesive 63 to the inner surface of the top portion 34 and thus, when a cap is removed as shown in FIG. 7 the thin metal or tape comprising the member 52 adheres to the bent up portion 60, although this is not necessary and does not occur in use with some of the relatively thicker tinplate seals 52 shown in Table I.

Thus, it may be seen that the present invention provides the advantages of affording a gas tight seal while at the same time retaining the other desirable features of a readily removable, and yet suitably rugged crown cap, namely, the retention of the slits or embosses in the case of tinplate crowns and the retention of the tab location substantially in the flange region where they are not subject to accidental opening or undesirable crushing or the like.

Thus, it will be seen that the present invention, as described above and is shown in the drawings, provides a novel orown cap for containers having desirable advantages and characteristics including those referred to above, as well as others which are inherent in the invention. I comprehend that certain variations and modications of the present invention may be made without departing from the spirit of the invention or the scope of the appended claims.

Iclaim:

1. In a crown cap for containers, said cap comprising, in combination, a metal cap body including a top portion, and, depending therefrom, a skirt portion including a radiused portion forming a transition surface integrally joining said top portion to said skirt portion, and, located substantially entirely in said skirt portion, at least two tab portions defined by cuts through said crown cap, said tab portions being attached at the bottom portions thereof at the lower peripheral edge portions of said skirt, and disposed in said top portion, at least one line of weakness for each tab portion, each of said lines of weakness extending at least partially inwardly from each of said tab portions, and, disposed in said cap body, an inner seal member of a resilient material, saidl material being relatively impermeable to gases when in a compressed condition, the improvement comprising, a metal-containing substantially gas-impermeable outer seal member extending substantially across the entire width of the inner seal ymember to render said crown cap substantially gas impermeable, said metal-containing outer seal member being disposed between said cap body and the top portion of said inner seal.

2. An improved crown cap as deiined in claim 1 in which said lines of weakness comprise, one radially inwardly extending cut for each of said. tabs, said cuts extending entirely through said top portion of said cap body.

3. An improved crown cap as defined in claim l in which said lines of weakness in said top portion of said cap comprise one radially inwardly extending embossed line for each tab.

4. An improved crown cap as defined in claim 1 in which said lines of Weakness comprise scored lines on the inside surface of said cap body, said lines joining the respectively adjacently disposed top portion of said tabs, thereby forming a plurality of chords which define a regular polygon inscribed in said top portion of said cap body.

5. An improved crown cap as defined in claim 1 in which said lines of Weakness comprise scored lines on the outside surface of said cap body, said lines joining the respectively adjacently disposed top portion of said tabs, thereby forming a plurality of chords which define a regular polygon inscribed in said top portion of said cap body.

References Cited by the Examiner UNITED STATES PATENTS 1,899,210 2/1933 Ramsay 21S-46 2,874,863 2/1959 Unger et al 21S-4() 3,118,556- 1'/1964 Amato et al. 21S-66 3,155,262 11/1964 Cros 215--46 FOREIGN PATENTS 1,240,145 7/1960 France. i

JOSEPH R. LECLAIR, Primary Examiner.

FRANKLIN T. GARRETT, Examiner. 

1. IN A CROWN CAP FOR CONTAINERS, SAID CAP COMPRISING, IN COMBINATION, A METAL CAP BODY INCLUDING A TOP PORTION, AND, DEPENDING THEREFROM, A SKIRT PORTION INCLUDING A RADIUSED PORTION FORMING A TRANSITION SURFACE INTEGRALLY JOINING SAID TOP PORTION TO SAID SKIRT PORTION, AND, LOCATED SUBSTANTIALLY ENTIRELY IN SAID SKIRT PORTION, AT LEAST TWO TAB PORTIONS DEFINED BY CUTS THROUGH SAID CROWN CAP, SAID TAB PORTIONS BEING ATTACHED AT THE BOTTOM PORTIONS THEREOF AT THE LOWER PERIPHERAL EDGE PORTIONS OF SAID SKIRT, AND DISPOSED IN SAID TOP PORTION, AT LEAST ONE LINE OF WEAKNESS FOR EACH TAB PORTION, EACH OF SAID LINES OF WEAKNESS EXTENDING AT LEAST PARTIALLY INWARDLY FROM EACH OF SAID TAB PORTIONS, AND, DISPOSED IN SAID CAP BODY, AN INNER SEAL MEMBER OF A RESILIENT MATERIAL, SAID MATERIAL BEING RELATIVELY IMPERMEABLE TO GASES WHEN IN A COMPRESSED CONDITION, THE IMPROVEMENT COMPRISING, A METAL-CONTAINING SUBSTANTIALLY GAS-IMPERMEABLE OUTER SEAL MEMBER EXTENDING SUBSTANTIALLY ACROSS THE ENTIRE WIDTH OF THE INNER SEAL MEMBER TO RENDER SAID CROWN CAP SUBSTANTIALLY GAS IMPERMEABLE, SAID METAL-CONTAINING OUTER SEAL MEMBER BEING DISPOSED BETWEEN SAID CAP BODY AND THE TOP PORTION OF SAID INNER SEAL. 